#jQuery

Earlier this week, I was helping a client of ours interface with a 3rd party widget on a site they work with. What the widget basically does is allow the user to input some information which is then POST’ed to another 3rd party site.

What our clients were looking to do was capture the information in the form before it was submitted, process it before the user left the page, and set any cookies on the user if necessary. Simple enough right? Use jQuery to trap the form’s submit event, do the processing dance, and then allow the form to submit normally.

So I implemented the code as described but for some reason the jQuery submit() handler was never being triggered. Perplexed, I looked through the actual widget code and it turns out that the widget was using a <a> tag with an onclick handler which eventually called document.someForm.submit(). Turns out, the jQuery submit() handler won’t trigger when a form is submitted in this fashion.

Thankfully, it’s relatively straightforward to get around this. You just need to override the form element’s submit() function with one of your own and then eventually call the original function once you’re done.

Earlier in the week, I was looking to customize how the Bootstraptypeahead() plugin was rendering the autocomplete options. Surprisingly, looking at the options listed on the plugin there is no way to specify a custom renderer function. Poking around a bit, I ran across this pull request on GitHub it looks like changes to the typehead() plugin have been tabled since it’s going to be replaced in Bootstrap 3.0 anyway.

I didn’t really want to customize our version of Bootstrap for a single page so I went on the hunt looking for a way to customize the renderer without modifying the plugin. Looking at how the typeahead() plugin is instantiated I noticed that a reference to the “Typeahead()” object with the render() method is actually stored using data() for the element it’s activated on. Because of that, it’s actually relatively straightforward to just overwrite the render() method on the specific element that you’ve activated typeahead() on.

Earlier today, I was adding a “slider” UI element to a project that was using Twitter Bootstrap as well as jQuery UI. Although they weren’t designed to work together, the two projects generally stay out of each other’s way since their CSS classes are namespaced pretty well.

Since jQuery UI was already loaded I naturally decided to just use the jQuery UI slider control to power the slider. One of the limitations with the jQuery UI slider is that it has no native way to show the current slider value over the slider handle, as a developer you have to display that number somewhere. Fortunately, the control has the event hooks neccesary to make this happen – specifically the slide event which is triggered everytime the slider is moved.

With Bootstrap also loaded, I decided to try and use the tooltip plugin to dynamically display the current value of the slider above the handle. Getting the initual tooltip setup was pretty straightforward. Check it out here.

But the issue is that even with the “slide” event, the Bootstrap tooltip plugin has no exposed method to force a reposition. The only way to get a tooltip to reposition itself is to hide it and then show it again. Obviously, that’s less than ideal since you get a noticible “jump” as the tooltip is hid and then shown again.

With this issue in mind, I decided to take a look at how the Tooltip plugin actually does the positioning. It turns out it’s really simple, the relevant code is on GitHub. Ok, so its easy to reposition them but how do you get the “right” tooltip div incase you have multiple sliders? Looking through the code, the Tooltip plugin actually uses the jQuery.data() function to store config options and additionally stores a reference to the correct div there. Getting a handle to the correct div is as easy as $(“#slider .ui-slider-handle:first”).data(“tooltip”).$tip

Looking at the actual plugin code, it’s simple enough to just copy that out and use it to reposition the tooltips. Check it out in action at http://jsfiddle.net/cqVPM/7/

A couple of days ago, we were looking to theme a set of Drupal 7 View filters that were also using AJAX to load the new View content. By default, the filters were rendering as a set of radio buttons so by default we were getting HTML that looked like this:

The problem was that given the design mockups we had, styling the filters to match with only CSS was going to be impossible. Writing a jQuery plugin to dynamically replace the filters with custom HTML was pretty straightforward but the tricky part was getting a notification that an AJAX request had completed so that we could reload the filters.

We managed to do this using the Drupal.behaviors Javascript object using code that looks similar to what is below:

Anyway, nothing to crazy but there doesn’t seem to be a ton of documentation about the Drupal.behaviors object.